Let’s find the biggest cities in South France:

Checking the daily newspapers of Marseille as a first city in the list we get the name ‘Le Petit Provençal’

At online archive Retronews.fr there is only mentioning of avalanche, no information about snow drifts on the national road

On the same online archive let’s find the Le Petit Marseillais newspaper. And it says that national road Grenoble - Briancon № 91 was cut off

And this is the right answer:

Used tools and resources

• Google text search
• French Newspapers Archive Retronews.fr